Electrochemical cells include, for example, lithium-ion cells. Such cells can be repeatedly charged and discharged. Cycling of cells can be accompanied by gas generation. Where a cell is contained in a package, heating or generation of gas can make the package swell. Where a package is received by an electronic device or system, such an increase in volume may result in damage to the device or system. Various technologies and techniques described herein may address gas generation and optionally other aspects of electrochemical cell operations.